Rodgers, BryanA. Mann, Sheila2026-02-222026-02-220033-2917PubMed:3489954ORCID:/0000-0002-2863-3737/work/206228169https://hdl.handle.net/1885/733805750Studies employing psychiatric rating instruments administered by lay interviewers need to demonstrate the reliability and validity of subject classification. In a national population study utilizing the short form of the Present State Examination, audiotapes of interviews were used to demonstrate the reliability of ratings. The classification of ‘cases’ was found to be related to self-reports of nervous trouble and help-seeking for such problems. Associations between the rate of psychiatric disorder and demographic factors were similar to those found in previous community surveys. In general, the method of psychiatric assessment was considered to be satisfactory. Recommendations are made for the monitoring of interviews in similar large-scale investigations.A recent investigation into factors associated with the occurrence of psychiatric disorders, which provided the data presented in this paper, is one study which illustrates the requirement for such a careful appraisal of the indices of disorder. The investigation in question, part of the Medical Research Council's National Survey of Health and Development (NSHD, the 1946 British birth cohort), utilized a short version of the ninth edition ofthe Present State Examination (PSE), as described by Wing et al. (1974 a). The PSE is a standardized interview with a well-defined procedure for eliciting and recording recent psychiatric symptoms. Symptom ratings can be classified using a set of rules which have been translated into a computer program (Wing & Sturt, 1978). In the form used for the NSHD, and with a sample drawn from a cross-section of the population, this instrument will identify mainly affective disorders. The shortened PSE has been used in several population studies, and the reliability of ratings made by interviewers with no prior psychiatric training has been a topic of particular interest (Cooper et al. 1977; Wing12en©1986 The authors198610.1017/S00332917000104360023011607